1. Field of the Invention
The present invention relates to improvement to and of the automatic centrifugal barrel finishing machine of the type which includes a turrent turning on its central axis at a high speed and carrying a plurality of barrels open at top for axial and orbital rotation, the improvement comprising a plurality of barrel holders rotatably and revolvably mounted to the turret and each having an upper stationary plate and a movable bottom plate for holding a barrel or barrels therebetween, the upper plate being carried by an inner shaft with a chuck and the bottom plate having a barrel mounting shaft to be engaged by the chuck, an indexing table which moves horizontally and vertically and rotates with predetermined indexing steps and sequence control means to control the above-mentioned operations in the predetermined sequence.
2. Description of the Prior Art
A conventional centrifugal barrel finishing machine operates at a high speed and with a high finishing efficiency, and is therefore known to have a wide range of use in the various industrial fields such as surface polishing, deburring, milling, stirring, mixing, chemical processing, etc. of workpieces together with abrasive or other media in the barrel containers. Disadvantages have been noted in accordance with the conventional machine, particularly with respect to the handling of top covers which are removably provided for covering and uncovering the barrels in operation, and the handling of workpieces and/or media for charging and discharging the same in the barrels, and in both cases the handling time requires a considerable length of time. The machine can itself complete its finishing or treating cycle in several minutes while the recharging interval of workpieces and/or media is relatively long, usually taking ten and several minutes, or several ten minutes when the number of barrels is increased.
In order to eliminate the above disadvantages, various solutions have been proposed. For example, the barrel holder mounted to the turret has a packing at the underside thereof, and the barrel is placed such that the open top edge of the barrel can be brought in intimate contact with the packing which can keep the barrel airtight or watertight only under pressure. In this case, the time required of handling the top covers is thus eliminated and the automatic handling of the barrels is thus permitted with the accompanying improved work efficiency. It is observed, however, that the barrel holding mechanism is not satisfactory so much so that it cannot hold the barrels securely, thus causing the barrels to slip out of the holding mechanism during the operation. On such event, the barrels may seriously damage the overall constructions of the machine.